Improvement in cornish engines



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JOHN STORER, OF PEEKSKILL, NEW YORK..

Letters Patent N 106,886, dated August 30, 1870; antcrlatcd August 18,1870.

IMPROVEMENT IN CORNISH ENGINES.

The Schedule referred to in these Letters Patent a'xd making part of theEsame To all whom 'it may concern Be it known that. I, Jol-1N S'rounn,of Peekskill, m the county of Testchester and State of New York, haveinvented a new and useful Improvement in Cornish Engines; and I dohereby declare the following to be a. full, clear, and exact descriptionthereof, which will enable those skilled in the art to make and use thesame, reference heilig had to the' accompanying drawing forming part ot'this specification, in which dwawing- Figure l represents a sectionalside elevation ot' this inveution.

Figure 2 is a front' view of the same.

Similar letters indicate corresponding parts.

This invention consists in the arrangement of an adjustable tappet incombination with the exhaustvalve of' the main steam-cylinder and withthe cataract-cylimler in such a. manner that, by the action of thecross-head on the tappet the exhaust-valve of the niain cylinder isclosed and the weight of the cataract-cylinder is raised and retained bya stop, and by v changing the position ot' the tapp'et the main pistoncan be arrested in its downward stroke at any desired point. i

The motion of the main piston is produced by means ot' an auxiliarycylinder, and the steam-valve of this auxiliary cylinder receives itsmotion through the cross-head and a turnier-rod, which connects with thevalve-stein by a slotted brac et carrying an adjustable slide, in such amanner that, by adj nsting the slide in the slotted bracket, therapidity of the valve motion ofthe auxiliary cylinder can be adjusted tothe desired speed ot the main piston.

With the tappet-rod is combined an adjustable cam and a trip-dog securedin the cross-head, in such a manner that the steam in the main cylindercan be cnt ottA at any desired part of the stroke.

lhe piston in the auxiliary cylinder is provided with grooves andsteam-passages, which 'are closed` by suitable lalves, and thesteam-ports open into the cylinder, at certain distances from its heads,in such a manner that the steam in the ends ot' the cylinder iscushioned, and at the same time the steam is enabled to act on thepiston at either end of its stroke.

In the drawinglhe letter A designates the steam-cylinder of a Cornishengine, which is 'provided with a piston, B, and which receives steamthrough a slide-valve, C.

This valve is so adjusted that it opens when the piston has arrived atthe lower end ot' its stroke, the steam being employed to raise Ithepiston, while said piston descends by its own gravity, combined with thegravity of the machinery attached to it.

In order` to regulate the descent ofthe piston, a cataract-cylinder, D,iscombincd with tlie exhaustvalve E.

On the stem of this exhaust-valve is mounted a .double-armed lever, l),which connects at one end with a rod, c, that carries a. tappet, d, andon its other end with a rod, c, from which is suspended the tri p-weightf ot'thc cat-aract-eylnder.

l The tappet-rod c passes through the. cross-head F of the main piston7and, as this piston approaches the lower end ot' its stroke, thecross-head strikes the tappet Za nd `the exhaust-valve is closed. At thesame time. the trip-weight f is raised, anda stop-lever, g, catchesunder a dog, h, projecting from the stem ot' the exhaust-valve, saidstop-lever being connected to a lever, i, which is subjected to theaction ot' a spring, j.

lhe lever t supports the plunger h of .the cataractcylindcr, and as thisplunger descends gradually and forces out the iiuid contained in the,bottom part ot'v j' against a spring catch, j", which is attached to arod, and extending from said plunger up through the weight. j

When the. plunger has been lifted to the required height, the springcat-ch is forced back by the action ot' a cam, f, attached to thecataract-cylinder, and the weight is permit-ted to rise the requireddistance, independent ot' the plunger.

lhe height to which the weight is thus raised may be regulated by ascrew-thimble that serves to regulate the length ofthe rod e, and thecorrect position of the exhaust-valve can thus be insured.

The exhaust steam is carried through a pipe, t, into the upper part ofthe main cylinder, whence it passes ott` through a pipe., m, so that thecylinder is not allowed to cool olf.

ABy adjusting the tappet tl on its rod c, the time when theexhaust-valve is closed can be adjusted, and the main. pistonA can becushioned inY its downward stroke to any desired extent, or its downwardmot-ion can be arrested sooner or later, as may be re quired.

lhe motion of the main valve is produced by an auxiliary cylinder, l1",the valve of which is provided with a stem, n, that connects, by afriction-clutch, o, with a rock-shaft, p. j

On this rock-shaft is mounted a lever, q, which connects with a slide,r, that is adjustable in a slotted bracket, s.

This bracket is mounted on a rod, t, which slides up and down iusuitable guides, and which carries two tappets, u.

These tappe'ts are situated in the path of a dog, 11, projecting fromthe cross-head of the main piston, and, as the piston approaches thebottom end of its stroke, the dog c strikes the lower tappet u, thetappetrod is depressed, the valvel of the auxiliary eylinder ismoved,steam is admitted to said cylinder, and the main slide-valve is opened,so as to admit steam into the lower end of the main cylinder, and themain piston begins its up-stroke.

The rapidity with which the valve of the auxiliary cylinderis throwndepends upon the position' of theV slide 'r iu the slotted bracket s.

If this slide Yis moved toward the center of the rock-shaft p, a smallerportion of the stroke of the main piston is required to throw theauxiliary valve than if the slide is moved further from the center ofthe rock-shaft.

The slide 1* is adjusted by a screw, fw, which extends throughout theentire lengt-h ot' the slotted bracket, and the friction-clutch 0 servesto allow the rock-shaft to -follow the action of the tappet-rod beyondthe stroke of the auxiliary valve.

By shifting the slide in the slotted bracket s, the valve-motion of theauxiliary cylinder can be adapted to the speed of the main piston.

'lhe dog o which acts on the tappets u, straddles a cani-rod, at', andit is subjected to the action of a spring, y, which has a tendency toforce the same out toward the tappet-rod.

As the cross-head rises the dog c comes in contact with the cam 7 on'therod x, and it is thereby forced back so as to release the upper tappetu, and the main pistou completes the balance of its Stroke without anyfurther effect-v ou the tappet-rod t.

'lhe tappets u are so adjusted that thevalve of the auxiliary cylindercompletes its stroke before the trip-dog w releases the upper tappet,and the camrod x is provided with a screw-shank and nut, so that the camcan be raised and lowered, and by 'these means the steam can be cut oli"at any part of the stroke of the main piston.

Tile piston G of the auxiliary cylinder isl provided with depressions,a1 a2, from which extend one or more openings, bl D, to the ends of saidpiston, and these openings are closed by valves c c?.

'lhe depressions' a* a2 are so situated that,wheu the piston hasfreachedeither end of its stroke, the corresponding depression is opposite oneof the steamports d* di, these steam-ports being made to pass into thecylinder at a certain distance from its heads.

If the piston G moves in the direction of the arrow marked on it in iig.1, the port Z1 will be closed before the piston has reached the end ofits stroke, and the steam which has not time to exhaust will cushionsaid piston.

During this lnotion, the valve c is` closed by the pressure of thesteam. Y

It' the piston has reached the end of its stroke, the depression alcornes opposite the port dl, and as steam enters throught-his port itpasses through the openings bl and lifts the valve cl, so as to drivethe piston down.

By this arrangement a simple way of cushioning the piston is produced,and it is obvious that this arrangement is applicable to allsteam-cylinders, provided their ports are properly situated.

I am aware that a compensatingr mechanism composed qf a hinged lever anda tappet-rod, one of which is made adjustable, in combination with anauxiliary cylinder, the piston of which actuates the main valve, is notnew, a similar arrangement being shown in my patent of September 7,1869; I donotptherefore, broadly claim such compensating mechanismwithout reference to its peculiar construction.

What l claim as new, and desire to secure by Letters Patent, is

1. The tappet-rod c, lever b, valve E,and stop-lever g, with thecataract-cylinder D, and cross-head F of the main cylinder,substantially as vshowu'and described.

2. The rod t, carrying the tappets u, and the slotted bracket s, incombination with the lever q, rockshaft y, diction-clutch o, andvalve-stern of the aux'- iiiary cylinder E' and with the cross-head ofthe main cylinder, snbstmftially as set forth.

3. The mechanism herein described for cutting olf the steam at any partof the stroke, consisting of a I trip-dog secured in the cross-head orany other part attached to the piston-rod, and of a device for releasingsaid trip-dog` at the required point, substantially as herein set forth.

4. The depressions al ai, openings?)l b2, and valves c c2, in the pistonof a stean'i-cylinder, constructed substantially as set forth.

JOHN STORER.

Witnesses W. HAUFF, E. F. KASTENHUBER.

